1. Field of the Invention
This invention relates to a frame structure for a saddling type vehicle such as a four-wheel buggy for driving on uneven ground.
2. Description of Background Art
A four-wheel buggy is generally constructed such that a pair of left and right vehicle body frames, for supporting an engine thereon, are formed substantially in a loop-like configuration from pipe members. In addition, at portions of a front portion of the vehicle body frames at which a front wheel suspension apparatus is provided, reinforcement pipes extend obliquely forwardly and rearwardly and upwardly and downwardly as viewed in a side elevation in an intersecting relationship. Further, in Japanese Patent Laid-Open Application No. Heisei 1-109186, a four-wheel buggy is disclosed wherein front end portions of a pair of left and right loop frames having a substantially loop-like configuration as viewed in a side elevation and supporting an engine thereon are connected to a box-like member and support portions for a front wheel suspension apparatus is provided on side faces of the box-like member.
When a front portion of a vehicle body on which front wheel suspension mechanisms are provided are formed from a large number of reinforcement pipe members as described above, since a large number of portions to be welded are involved, many welding steps are required and a high cost is required. In addition, quality control is difficult due to the influence of heat upon welding.
Meanwhile, where a front portion of a vehicle body is formed as a unitary box-like member as disclosed in Japanese Patent Laid-Open Application No. Heisei 1-109186, the number of welding steps is reduced advantageously. However, since the entire front portion of the vehicle body has a high rigidity, if, during driving on uneven ground, an impact is inputted to a lower portion of the front portion of the vehicle body from the ground side, then the impact is transmitted to the entire vehicle body frame, and therefore, also it is desired that the front portion of the vehicle body should be constructed so as to absorb an impact to some degree.